Jump to content
SAU Community

Recommended Posts

Good morning legends.

While scanning yahoo Japan auctions I came across someone selling an RB25de Neo vct solenoid and cam gear as an upgrade for the RB25det Neo... They state that the 25de vct has 30° variability and can give gains to the 25det. I'll attach a screenshot of the auction page.

IMG_2896.jpg

 

Can anyone please confirm how many degrees of variability the rb25det s1/2 and rb25det Neo vct system has??

Cheers (:

I wouldn't count on it fitting older 25s.  The advert explicitly talks about ONLY putting it on Neo 25s. (and 26s as a retro with the other stuff you need to do).

I don't know for 100% sure, but I think that the difference between cam front end details on older 25 to Neos means they are not same same.

Yeah for sure man, Im not 100% clear on the difference in vct hardware between Neo and s1/2 either, but I think the solenoid body may be slightly different and I think the keyway on the cam/cam gear is different between the two as well so as you say, probably not interchangeable.
Still though, I'm interested in what the det Neo and det s1/2 vct variability is [emoji848] it could be a nice little gain for very little $$ for a det neo..

The solenoid is different and does not work in non neo engines, the vct is different too,  as GTS boy said they are specific to neo engines. Neo vct cuts in much earlier, from idle, and is active all revs to 5700rpm for turbo and 5400rpm for n/a wheras earlier RB25 ranges are 1050 - 5700 and 1050 - 5400 respectively

 

Neo and non neo use different actuation methods so solenoids and oil galleries are different. They are wrong to say the pulley has variability if they imply its incremental. It only phases from 0 to 30 degrees and nothing inbetween, this is a big point of confusion with the rb25 vct.

 

22 minutes ago, Dobz said:

Neo and non neo use different actuation methods so solenoids and oil galleries are different. They are wrong to say the pulley has variability if they imply its incremental. It only phases from 0 to 30 degrees and nothing inbetween, this is a big point of confusion with the rb25 vct.

 

Yep, it is either full on or off there is no variability . Lots of Bullsh*t floating around about this system, its quite basic.

20 hours ago, Rusty Nuts said:

The solenoid is different and does not work in non neo engines, the vct is different too,  as GTS boy said they are specific to neo engines. Neo vct cuts in much earlier, from idle, and is active all revs to 5700rpm for turbo and 5400rpm for n/a wheras earlier RB25 ranges are 1050 - 5700 and 1050 - 5400 respectively

Regardless of NEO or non-NEO the RPM where it is enabled or disabled is 100% configurable if you're not using a PowerFC or Stock ECU.

The window where it stays on should be tuned till when torque starts to decay, of course this is all dependant on what parts have been bolted to the motor.

Generally for me, I will do one run with it turned off and one run with it turned on past max torque ie close to red line and overlay the derived torque graph. The intersection point is optimally where it is turned off. Also once off, the motor will happily take more timing :)

 

1 hour ago, GTSBoy said:

Also, according to my quick look at Nistune just then, Neo turbo switches at 5400rpm.

I am quoting Tomei and a standard ECU there was no mention of Nistune in his enquiry. I am using Nistune in mine and using the start point at 1050rpm because the VCT internals lasts longer physically if its actuated when oil pressure is higher, they tend to "bounce" internally at idle

2 hours ago, Dose Pipe Sutututu said:

Regardless of NEO or non-NEO the RPM where it is enabled or disabled is 100% configurable if you're not using a PowerFC or Stock ECU.

Regardless it just doesn't bloody fit so this argument is off subject.

2 minutes ago, GTSBoy said:

Nistune is a standard ECU.  The ROM is sucked out of a real Neo ECU..  I just read the number off the screen.

Regardless it just doesn't bloody fit so this argument is off subject.

2 hours ago, Rusty Nuts said:

I am quoting Tomei and a standard ECU there was no mention of Nistune in his enquiry. I am using Nistune in mine and using the start point at 1050rpm because the VCT internals lasts longer physically if its actuated when oil pressure is higher, they tend to "bounce" internally at idle

Huh? Vct isn't active at idle as it makes the idle lumpy due to extra overlap.

never heard of anyone wearing out a vct setup..

  • Thanks 1
40 minutes ago, Ben C34 said:

never heard of anyone wearing out a vct setup.

I have, and they make a nasty knocking noise when they go try googling nissan vct rattle only 14700 hits

Edited by Rusty Nuts
1 hour ago, Ben C34 said:

never heard of anyone wearing out a vct setup.

Yes you have, you answered a similar post back in AUGUST 2015 RB25DET VCT Knocking and i quote you 

"Man, I meant the whole vct unit along with cam gear.

I thought it was kind of obvious.

Changing just the actual gear part is a bit pointless, it's the actual vct actuator part of the car gear assembly that needs to be changed"

So whats your game mate

Edited by Rusty Nuts

Wow. Got me there. Goes to show I don't remember everything I have said/written 3 years ago.

 

I don't think it's an issue that needs addressing or accounting for in the tune, shit just wears out.

 

My game is Q-Bert. Or Pitfall. I am a simple man.

 

  • Like 2
  • Haha 1
17 hours ago, Rusty Nuts said:

I have, and they make a nasty knocking noise when they go try googling nissan vct rattle only 14700 hits

Perhaps on SR20s not RB25s

Different design

2 hours ago, Dose Pipe Sutututu said:

Perhaps on SR20s not RB25s

Different design

different design sure! Same reason build up of sludge and /or low oil pressure. But hey, past months experience ,if I say its white you will say its black are you 5 years old.

G e e z u z .
I realise now the title is a little misleading... Im mainly referring to weather or not the 25de neo vct gear had more degrees of adjustment over the 25det neo vct gear... sorry I didn't put "neo" after the last "Rb25det" in the topic title.. as I stated in my second comment, I'm aware there are differences between neo ans s1/2 and they aren't compatible..

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Nah it factory manual not sure about ratio but it looks like there’s been some work at the rear 
    • so I need a new speedo cable 
    • Throwing my spoon to the soup here a bit.  When I installed a 044 back in 2012, along with the direct power mod, the car became very difficult to start. To a point I burned one starter motor as I was late for work and tried to get the thing going. With some tuning and careful use of gas pedal when cranking it became bearable. Trying to make this short as possible, but the 044 died after 2-3 years, after which I went with an AEM 320lph pump, which also died after about 4 years to my dismay. After that I went with a Nismo pump, and while trying diagnose an emissions problem, I noticed for the first time that my fuel pressure was 5bar/72psi on idle, and that removing the vacuum line did nothing. After monitoring the situation, and removing the direct power feed and going back to FPCM in attempts to remedy it, I noticed there was fuel in the pressure regulator vac line. Kept the FPCM, installed AEM external regu and the car became sooo much better in every way, including starting. And I had driven it like it was for 11 years.. Anyway, I agree these are likely two different problems, and the FP problem you just haven't noticed before. I do not know much about haltecs, but what first came to mind was the CAS, which probably is not there any more. So how is the wiring from haltec to gauge cluster? How is the battery voltage and alternator?
    • Your car was auto before? You have different diff ratio (auto vs manual i think? or n/a and turbo?)
    • +1 for getting a screen off alibaba, CarPlay/Android Auto is vastly better than whatever navigation cars had 10 years ago. I got an Android screen for my 2015 BMW, huge difference. Fully compatible with factory stuff including iDrive controls.
×
×
  • Create New...